Impact tool assembly



Sept. 24, 1968 K. H. HOEN 3,4 9

IMPACT TOOL ASSEMBLY Original Filed Feb. 14, 1964 i '2 She t s-Sheet 1IN VENTOR.

KENNETH H. HOEN U ATTORNEY p 24, 8 K. H. HOEN IMPACT TOOL ASSEMBLYOriginal Filed Feb. 14, 1964 I 2 Sheets-Sheet z IN VEN TOR. KENNETH H.HOEN ATTORNEY United States Patent 3,402,969 IMPACT TOOL ASSEMBLYKenneth H. Hoen, 2396 Orchard Lane, Littleton, Colo. 80120 Originalapplication Feb. 14, 1964, Ser. No. 345,006, now Patent No. 3,318,392,dated May 9, 1967. Divided and this application Mar. 28, 1967, Ser. No.626,529

4 Claims. (Cl. 29993) ABSTRACT OF THE DISCLOSURE The rectangularconnecting end of an impact tool is releasably clamped within the slotof an attaching head by one or more wedges disposed in guide slots alongone side of the blade-receiving slot, and a locking member is removablypositioned behind each wedge and is adjustable to tigthen each wedgeagainst one side of the connecting end of the tool.

This is a divisional application of Ser. No. 345,006, filed Feb. 14,1964, now Patent No. 3,318,392.

The impact tool is of generally T-shaped configuration including anattaching head and an elongated generally rectangular blade stock havingopposite, outwardly divergent side portions of transversely concaveconfiguration which terminate in an elongated cutting face squared tothe blade axis. The blade stock can be detachably clamped within .ablade-receiving slot in the attaching head through the combinedutilization of wedges inserted in the slot and locking screws to forcethe wedges into clamping engagement with one end of the blade within theslot.

This invention relates to tool attachments and tools for powered hammersand the like; more particularly this invention relates to novel andimproved means for interchangeably mounting different tools on poweredhammers depending upon the work to be performed, and additionally toimpact tools that are adaptable for use in association with poweredhammers for the specific purpose of cutting and breaking concrete,asphalt, rock and other hard surfaces in an efiicient and reliablemanner.

The advantages and features of the tool attachment and tool of thepresent invention can be best appreciated from a consideration of theiruse in association with powered hammers of the type used for performinga number of different tasks, such as, for breaking and cutting concrete,asphalt and similar materials, as well as for tamping earth fills,digging trenches and other earth working operations. Necessarily,different tools are attached to the lower end of the hammer mechanismaccording to the character of the work to be performed, and the hammermechanism and attached tool are reciprocated or otherwise operated todeliver a series of impacts or blows under considerable force to thesurface being worked. Accordingly, it will be appreciated that it ishighly desirable to afford some rapid, dependable means for rigidly butreleasably attaching each different tool in place, and specifically insuch a way that the tool will not have a tendency to loosen or in anyway shift in delivering a succession of blows to the work surface.

In cutting and breaking relatively hard surfaces such as bedrock,concrete or hard asphalt areas, it is also desirable to utilize a toolwhich is capable of clean, rapid, straight-line cutting with a minimumof fracturing of the material. In this relation, the cutting tool is soconstructed and arranged in association with the tool holder that theassembly can be mounted on hammers of different types, and also the toolcan be reversibly mounted to "ice compensate for the effects oflocalized wear on the cutting face.

Accordingly, it is a principal and foremost object of the presentinvention to provide a hammer tool attachment for powered hammers thatis characterized by being conformable for use with different types ofhammers and of being self-adjusting for clamping and accommodatingdifferent types of tools in carrying out cutting, breaking, tamping andsimilar operations.

It is another object of the present invention to provide for a novel andimproved means for removably attaching different tools to a poweredhammer mechanism and wherein the tools can be rapidly connected andremoved in a safe, efiicient manner by one person; and further, whereineach tool in attached relation is rigidly clamped and wedged againstloosening or displacement in use.

It is a furtherobject of the present invention to provide for a hammertool attachment characterized by providing a relatively broad surfacearea of connection between the hammer head and tool while at the sametime being formed of a minimum number of parts and requiring a minimumnumber of operations in connecting and removing each tool; andfurthermore, wherein the clamping arrangement employed as part of thetool attachment will permit reversible mounting of each different toolto minimize the effects of localized wear on the tool.

It is a still further object of the present invention to provide for anew and useful tool for cutting and breaking hard surfaces such as rock,concrete and asphalt wherein the tool is characterized by having a bladewhich will accomplish rapid straight-line cutting Without fracturing thematerial and will avoid the adverse effects of wear under repeated use;moreover, to provide a tool blade removably connected to the attachinghead of the tool in such a way as to permit replacement of the blade asrequired without replacement of the entire tool, and wherein the bladeis firmly locked in place so as to effectively form an integral part ofthe entire tool and attachment with the hammer head.

The above and other objects, advantages and features of the presentinvention will become more readily understood and appreciated from aconsideration of the following detailed description of alternate formsof the present invention taken together with the accompanying drawings,in which:

FIGURE 1 is a perspective view of a hammer tool attachment consisting ofa tool holder and cutting tool in attached relation on the lower end ofa hammer head.

FIGURE 2 is a front fragmentary view in elevation illustrating therelationship between parts comprising the preferred form of tool holderin attached relation to the hammer head.

FIGURE 3 is a view in detail of one form of tool adapter plate formingpart of the tool holder assembly.

FIGURE 4 is an enlarged elevational view of a preferred form of clampdefining a part of the tool holder shown in FIGURES 1 and 2.

FIGURE 5 is an enlarged end view of the preferred form of clamp.

FIGURE 6 is an enlarged top view of the preferred form of clamp.

FIGURE 7 is an enlarged elevational view of the cutting tool shown inFIGURE 1.

FIGURE 8 is a bottom plan view of the cutting tool illustrated in FIGURE1.

FIGURE 9 is a front elevation of a tamping device having an attachinghead formed for use in association with the preferred form of toolholder assembly, in accordance with the present invention.

FIGURE 10 is a front view of a modified form of cutting tool showing theparts in assembled relation.

FIGURE 11 is a side view of the blade attaching head for the modifiedform of cutting tool shown in FIG- URE l; and

FIGURE 12 is an enlarged view of the wedge locking device used inassociation with the blade attaching head shown in FIGURE 10.

Referring in detail to the drawings, a preferred form of hammer toolattachment is designated generally at in FIGURE 1 and which is broadlycomprised of a tool holder assembly 11 for attachment of a cutting tool12 to a hammer head 13. The hammer head illustrated is merelyrepresentative of various forms of impact members or weights which inaccordance with conventional practice, in a manner not shown, aresuitably mounted for reciprocation in a hammer guide frame. Forinstance, the hammer can be secured to the lower end of a ram extendingfrom a ram cylinder, and the ram is reciprocated to deliver a series ofimpact blows through the tool against the work surface; and typicalexamples of powered hammers of this general type or disclosed in PatentNo. 2,659,584 to Dorkins and Patent No. 2,335,172 to Cornett.

A principal feature of the present invention resides in the constructionand arrangement of the tool holder assembly 11 which, as will be notedfrom FIGURES 2 and 3, consists of an adapter plate 15 and clampingmembers 16 adjustably secured in spaced parallel relation to theundersurface of the adapter plate 15. It is emphasized that the adapterplate serves only as a means for conforming the tool attachment for usewith hammer heads of different sizes and constructions and accordinglyis specifically designed for direct connection of the clamping membersand tool attaching head thereto. Thus, the adapter plate 15 is providedwith outward bores 18 aligned with threaded apertures 19 in the bottomof the hammer head for threaded insertion of cap screws 20. In connectedrelation, the adapted plate provides a relatively fiat downwardly facingseating surface 22 with spaced rearwardly disposed positioning lugs 25projecting downwardly therefrom; threaded bores 25 spaced inwardly ofeach of the apertures 18 and extend upwardly through the major thicknessof the plate for connection of the clamps 16 in a manner now to bedescribed.

Broadly, the clamping members 16 are formed to rigidly but releasablysecure different tools against the seat formed either at the bottom ofthe hammer head or the undersurface of the adapter plate, as the casemay be, and in such a way that the clamps will form longitudinalguideways for positioning of the tool in loosely supported relation,after which the clamps are tightened to rigidly hold the tool in placeboth against loosening or lateral displacement. To this end, and as bestseen from FIG- URES 4 to 6, each clamp is defined by a relatively thickelongated body portion having a top angularly relieved surface portion31 and a shoulder 32 projecting laterally and inwardly from the lowerpart of the body, the shoulder 32 forming a guideway along the seatingsurface 22 for insertion of one side of the tool 12. Preferably, eachshoulder has top wedging surface portions 40 which incline downwardlyand inwardly toward one another from opposite ends and terminate in ashallow recessed area 41. Opposite ends of the body include bores 34extending vertically therethrough and a shallow spherical recessed area35 is formed at the entrance to each bore. Spaced intermediately betweenthe bore 34 is an upwardly directed spring-receiving opening 36 for acompression spring 38 as indicated in FIGURES 1 and 5. To adjustablysecure the clamps in spaced facing relation along opposite sides of theadapter plate 15, cap screws 42 are passed upwardly through the bores 34and into the threaded apertures 25 in the adapter plate. Each cap screw42 is provided with a spherical washer 44 to seat in the recess 35 ofeach bore 34 and in this way to prevent any lateral shifting of theclamps and afford more uniform distribution of pressure against thescrews and clamps when in attached relation. On account of the slopingsurfaces 31 it will be noted that the shoulders 32 will be drawnupwardly and somewhat inwardly, upon inward threading of the screws, soas to be self-adjusting according to the thickness of the clamp-engagingportions on the tool.

In order to cooperate with the tool holder to establish rigid clampingengagement between the tool and the hammer head as shown in FIGURES 7and 8, the tool 12 is of generally T-shaped con-figuration with anattaching head 59 forming a top relatively flat seating surface 51, acentral recessed area 52, and shoulder portions 54 projecting laterallyin opposite directions from the upper end of the tool. The shoulders 54are formed with clamp-engaging undersurfaces 55 complementary to theinclined shoulder surfaces on the clamps so as to be wedgingly engagedby the shoulders 32 when the shoulder portions 54 are inserted in theguideways and the clamps are drawn upwardly by the screws 42.Preferably, the attaching head is further characterized by beingsquare-sided so that opposite sides 56 will similarly defineclamp-engaging shoulders dimensioned for insertion in the guideways inthe event it is desired to turn the tool 90 from its disposition shownin FIGURE 1. By forming the head in this manner, the hammer operator canpreset the clamps to provide the required spacing between the shoulders32 and seat 22 according to the thickness of the shoulders 54, and thesprings 38 assist in this by urging the clamps downwardly against thespherical washers so that the clamps need not be held or positioned whenthe attaching head is inserted through the guideways. Thus, the operatorcan by grasping the tool align the shoulders 54 with the guideways andadvance the shoulders along the guideways until the back surface of theattaching head abuts against the positioning lugs 24, whereupon theinclined surfaces are properly aligned with the surfaces 40 on theclamps. By tightening the cap screws the shoulders 32 are urged upwardlyand inwardly to clamp the tool head 50 rigidly against the seatingsurface 22. The central recessed area 52 merely assures even contactbetween the abutting surface portions on the adapter plate and tool headand prevents possible misalignment between the abutting surfaces due touneveness or non-uniformities in the center area.

In the cutting tool 12 shown in FIGURES 7 and 8, a blade shank 60 isformed as an integral part of the tool and is particularly adapted foruse in cutting or breaking concrete, bedrock, asphalt and otherrelatively hard, thick surfaces. For this purpose, the blade shank 60first tapers outwardly from a relatively broad reinforcing portion 62then diverges downwardly therefrom and terminates in an elongated,relatively narrow cutting face 64 which is normal or squared to theblade axis. The cutting face 64 gradually increases in width from thecenter to opposite ends 65 since in use the major wear will take placeat opposite ends of the tool, and accordingly the increased width givento the cutting face will compensate for any tendency of the ends tobecome somewhat tapered relative to the center and which in penetratingdifferent rock surfaces would otherwise have a tendency to stick anddevelop fractures in the surfaces away from the point of impact. Inorder to maintain a uniform cross-sectional area for the cutting faceafter continued wear and sharpening, the sides 66 are given a concaveshape in a plane transverse to the blade axis and, along with oppositeend surfaces 65, are downwardly divergent away from the reinforcingportion 62 so as to form sharp cutting edges or corners 68 along theperiphery of the cutting face.

Generally, the tool will be positioned as illustrated in FIGURE 1 withthe cutting face 64 having its major axis aligned with the direction ofadvancement of the hammer vehicle, although as hereinbefore mentionedthe tool may be turned at right angles with the cutting face transverseto the line of travel. Under repeated blows, if the cutting face beginsto wear unevenly the tool may be reversed. In any event the principalwear will take place toward the end of the cutting face, but aspreviously noted this is compensated for by the widened cutting surfacetoward the ends together with the divergent sides and ends.

A tamping device 70 is illustrated in FIGURE 9 having a tool attachinghead 50 which in every respect is identical to the attaching head 50shown in FIGURES 7 and 8, and this being shown merely to illustrate theadaptation of the tool head for different types of tools. Broadly, inthe tamping device illustrated, downwardly divergent walls 72 terminatein a relatively broad tamping head 73 which may be conventionally usedin compacting or leveling ground surfaces. Again, the tamping device maybe reversed or merely turned 90 since the head is square-sided to formtwo sets of shoulders 54.

A modified form of cutting tool is illustrated in FIG- URES to 12 inwhich a blade stock 80 is detachably connected to an attaching head 82by means of wedges 83 and adjustable wedge-locking members 84. Again,the attaching head '82 is provided with shoulders 54 and clamp-engagingsurfaces 55 identical to those formed on the attaching head 50 shown inFIGURES 6 and 7; and the blade stock 80 assumes the same form as theblade shank 60; however, the upper end '86 of the stock is proportionedto fit into a longitudinal, downwardly directed slot 87 openingoutwardly from the head 82. Extending along one side of the slot 87 arewedge-shaped guide slots 88 each for insertion of a wedge 83, shown inFIG- URE 12. A pair of adjustable locking members 84 are shown each inthe form of a lock nut 90 which is removably inserted in a recess behindand in communication with each guide slot 88 and locked against rotationby the sides of the recess, and a socket head screw 91 extendingdownwardly through each lock nut 90 against the top surface of thewedge. The screws 91 are accessible from the top seating surface of thehead 82 for downward adjustment in order to force the wedges downwardlyand inwardly against the side of the blade element. Thus, the wedges 83and wedge-locking members 84 may first be inserted within the slots 88followed by insertion of the upper end of the blade stock, and bydownward threading of the locking members 84 against the wedges willhold the blade securely in place. Once the blade is connected to theclamp head 82, the assembled tool can then be clamped in place to thelower end of the hammer by the tool holder assembly.

It will be evident that different tools, such as, tamping devices,asphalt cutters, pavement breakers and the like may be appropriatelyformed with an attaching head 50, or in some instances a clamp head 82,of the type described so as to make each tool conformable for attachmentin cooperation with the tool holder assembly to various differentpowered hammers. Of course, the clamp head and wedge locking device maybe used for detachably connecting different types of blade elements sothat only one clamp head need be furnished and only the blade stockreplaced as it becomes worn, or where substitution is required inperforming different operations. Moreover, as stated, the tool holderassembly may be defined merely by the spaced clamps and attaching headwithout the adapter plate where the hammer head is designed for directconnection of the clamps. It is therefore to be understood that variousmodifications and changes may be made in the construction andarrangement of parts comprising the forms of invention illustrated anddescribed without departing from the spirit and scope of the presentinvention as defined by the appended claims.

What is claimed is:

1. In a powered hammer, an impact tool for cutting and breaking hardsurfaces, said tool being of generally T-shaped configuration andcomprising a head, an elongated, generally rectangular blade stockdetachably connected to said head and extending forwardly therefrom,said shank having downwardly divergent sides and ends terminating in anelongated cutting face squared to the stock axis, the cutting faceprogressively increasing in width toward the divergent ends of saidstock, said impact tool including a head provided with a blade-receivingslot opening forwardly from one end of said head with a guide slottapering forwardly along one side of said bladereceiving slot, saidblade stock having a connecting end dimensioned for insertion withinsaid blade-receiving slot, a wedge positioned within the guide slot towedgingly engage one side of the connecting end of said blade stock, andlocking means disposed in an opening behind said guide slot beingaccessible from the end of said head opposite the blade-receiving slotand being movable to force said wedge forwardly against the side of theconnecting end of said blade to hold said blade in clamping engagementwithin the blade-receiving slot.

2. An impact tool for powered hammers and the like comprising anenlarged head including a generally rectangular blade-receiving slot inone end of said head opening forwardly from the end of said head with aguide slot tapering forwardly along one side of said bladereceivingslot, a wedge positioned in the guide slot, and a blade having aconnecting end dimensioned for endwise insertion to fit within theblade-receiving slot with said wedge engaging one side of the connectingend of said blade, and locking means removably disposed in an openingbehind said wedge abutting the rearward end surface of said wedge, saidlocking means being accessible from the end of said head opposite theblade-receiving slot and being movable to force said wedge forwardlyagainst the side of the connecting end of said blade so as to hold saidblade in clamping engagement within the bladereceiving slot.

3. An impact tool according to claim 2 in which a pair of spaced guideslots are arranged in side-by-side relation to one another along oneside of said blade-receiving slot, a wedge positioned in each guide slotto engage one side of the connecting end of said blade stock, and saidlocking means being defined by a removable lock nut and adjusting screwdisposed behind each of said wedges, each screw being independentlyadjustable to force each of said wedges forwardly against the side ofsaid connecting end whereby to releasably locking said blade stock inclamping engagement between said wedges and the opposite side of theguide slots.

4. An impact tool comprising an enlarged head including a generallyrectangular blade-receiving slot in one end of said head and openingforwardly from the end of said head, and a pair of guide slots arrangedin side-by-side relation to one another within the head and along oneside of and in communication with said blade-receiving slot, a bladehaving a generally rectangular connecting end being dimensioned forendwise insertion within the blade-receiving slot, a wedge memberpositioned in each of the guide slots for engagement with laterallyspaced surface portions on one side of the connecting end of said blade,and an adjustable locking member being removably disposed in an openingbehind each wedge and being independently adjustable to force eachrespective wedge member forwardly against the side of the connecting endof said blade so as to hold said blade in clamping engagement within theblade-receiving slot.

References Cited UNITED STATES PATENTS 1,403,847 -1/ 1922 De Armond27987 1,880,623 10/1932 Williams -4 16 2,659,583 11/1953 Dorkins 9449 X2,7 89,826 4/ 1957 Procter 27987 3,006,424 10/196'1 Dahlin et al.'175414 X FOREIGN PATENTS 9,643 5/ l880 Germany.

'ERNEST R. PURSER, Primary Examiner.

